The Palestinian flag represents all Palestinian Arab aspirations regardless of party. It belongs to the Arab Revolt grouping of Arab flags and is a deliberate copy of the Jordanian flag (minus the star), which presumably represents the historical link to 1920-23 when Palestine and Transjordan were one territory. I think the flag was adopted in 1964 at the creation of the PNC and PLO, possibly a little later. It was definitely in use by 1974 when the Arab League declared the PLO the sole representative of all Palestinians and the UN granted the PLO observer status. There was no single Palestinian authority prior to 1964 that could have created a flag.T.F. Mills, 13 Dec 1995

There are basically three of our flags. The Common Flag is flown on a daily basis in representative offices such as ours, and is a triband (from top to bottom: black, white, green) with red triangle pointing to the middle of the white band. The other two are the Official and the Presidential flags. (...) In reference to the colour, this remains uncertain as there are no real specific colours. The green for instance could vary from turquoise to forest green.Al Bitar (Palestinian Embassy at Bucharest), 15 Feb 1999

The protocol manual for the
London 2012 Olympics (Flags and Anthems Manual
London 2012 [loc12]) provides recommendations
for national flag designs. Each
NOC was sent an image of the flag,
including the PMS shades, for their approval by LOCOG. Once this was obtained, LOCOG produced
a 60 x 90 cm version of the flag for further approval. So, while these specs may
not be the official, government, version of each flag, they are certainly what
the NOC believed the flag to be.
For Palestine: PMS 032 red, 355 green and black. The vertical flag is simply the
horizontal version turned 90 degrees clockwise.Ian Sumner, 10 October 2012

The pre-2006 flag had the triangle prescribed to reach fly-wise 1/2 of its width (base), i.e. 1/4 of the flag length. The 2006 legislation changed the flag description so that the triangle is reaching 1/3 of the flag length. The construction sheet differs in that the dimension indicated by 3 is replaced with 4 (and then everything should be halved :)Željko Heimer, 21 Jan 2012

An article by Jan Oskar Engene in the Autumn 2007 issue of Nordisk Flaggkontakt [nfk07a], the journal of the Nordic Flag Society, reports two acts adopted by the Palestinian National Authority in late 2005 and early 2006, describing the flag and regulating its use. Jos Poels has located the documents online (machine-translated titles):

2005 PA Flag Act ("The Law of the sanctity of the Palestinian flag number (22) for year 2005, 22.12.2005")

2006 PA Flag Act ("Law No. (5) of 2006 amending some provisions of the Law of the sanctity of the Palestinian flag number (22) for year 2005, 17.02.2006")

The online edition of the New York Times has a collection of photos from President Arafat's burial in Ramallah. (...) It appears that vertically positioned PS flags are – at least in this case – positioned so that the black stripe is on the right, as seen by a viewer. (This seems to make sense in a culture reading from right to left.)
"Thorsten," 13 Nov 2005

A photo of a Palestinian flag displayed vertically; as usual, the black (top) stripe is to the "sinister" (observer's right) in contrast to European practice.

I would like to offer a correction to the headline of the Palestinian entry. As far as I know,
the Arabic article "al-" is not attached to the name "Filisteen."
There are certain place and county names which are preceded by "al-"
(the equivalent of "the" in English), but Palestine is not one of them.
A few other corrections – I think "Filisteen" is a better transcription
(as used later in the adjective: "al-filistinieh"), but perhaps it would be best
to consult an Arabic speaker, since there are so many dialects and variants in pronunciation.
In "al-sulta" the first "l" should be omitted – "a-sulta" or "as-sulta."
This "l" is written but isn't pronounced, because there is an assimilation of the "l" to the "s."Dror Kamir, 27 Apr 2003